Since the biggest feature of a mobile device is its mobility or portability, the mobile device depends entirely on its battery for power supply. In this mobile device, therefore, it is very important to secure an extended lifetime of the battery by using the battery in a very efficient and stable manner.
In order to secure an extended lifetime of the battery, studies have been made in diverse aspects. There are, for example, a study to increase the battery capacity itself through high integration of the battery, a study to reduce power consumption of the battery by way of the system architecture level through the adoption of a low power-consumption design, a study to detect and reduce unnecessary use of the battery, and so on.
In studies on how to stably extend a lifetime of the battery by detecting and reducing unnecessary use of the battery, a battery drain is the major target being detected or monitored. The battery drain is a phenomenon that the battery drains more quickly than normal due to unnecessary processes or abnormal operations of the mobile device. In relation to the battery drain, there have been studies to estimate the amount of available time remaining on the battery by way of a circuit level or through simulations. A recently developed technique involves a statistical approach to estimate available time of the battery.
The study on abnormal power consumption of the battery is usually done by mobile device manufacturers. Examples of the abnormal power consumption include the operation of an unnecessary process, changes in propagation environment (e.g., strong-weak electric field, superposition, existence of propagation shadow region, interference, etc.), frequent changes in communication modes (e.g., mode change between CDMA 1x and CDMA 1x EV-DO), an influence from a service type of a radio base station in case of a frequent operation of keys and a use of additional functions offered by Internet, excessively bright lighting/unnecessarily long use of lighting (e.g., LCD, keypad lamp, backlight or the like), excessively loud sound system/unnecessarily long use of sound system (e.g., speaker, hands free speaker or the like), receiving and reading all kinds of spam messages, different habits of each user, and so on. This information on the causes as disclosed above helps detect abnormal power consumption of the battery.
Meanwhile, a variety of studies on estimating available time of the battery have been made to date, but there were few studies on methods or devices for detecting abnormal power consumption of the battery using estimated available time of the battery. In other words, there are no practical methods or devices to diagnose and detect the abnormal or unnecessary power consumption of the battery in the early stage.
Therefore, although the possible abnormal power consumption has been already analyzed as noted earlier, the mobile device manufacturers failed to prevent or detect the problem in the early stage.